English

Abstract

The aim of the study was to evaluate the variations in the rumen ecosystem at genus level and predicted functions of rumen bacteria by using whole crop corn silage (WCS), whole crop rice silage (WRS) or rice straw (RS) as forage sources in beef cattle ration. Ruminal digesta samples from 10 bulls per treatment were collected at day 60 of experimental period. The PCoA plots based on the Bray-Curtis distance matrix (BDM) expressed separation between WRS and WCS , WRS and RS using PC1 (P<0.05, 45.56%). The PCoA plots based on BDM also expressed separation among WRS, WCS and RS group using PC2 (P<0.05, 11.95%). Microbiota composition resutls at genus level showed that the most abundant genera were Prevotella (13.37%) and Ruminococcus (4.00%). Comparison of treatments represented that Prevotella, Treponema and Anaerostipes were higher in bulls fed WCS forage. Clostridium, Anaeroplasma and RFN20 were higher in bulls fed RS forage than animals fed WCS and WRS. Butyrivibrio was higher in WRS and RS treatments than WCS treatment group. Pseudobutyrivibrio was higher in bulls fed WRS forage than animals fed RS and WCS forage. Fibrobacter was higher in RS and WCS as compared to WRS. The results of functional alteration of rumen microbiota in different experimental groups represented that the leading modified function of the microbiome was the transporter. Based on findings of current study, it is concluded that microbial community at genus level in the rumen of bulls was highly altered by forage type.